In recent years, randomly accessible, and high density removable media have become popular as a recording medium used in a video camera for broadcasting operation. Such a removable media includes, for example, an optical disk, a magneto optical disk, a magnetic disk, and a semiconductor memory or the like. The recorded video data and audio data are stored in an internal or external disk drive used with an editing apparatus, and transmitted to a hard disk drive (HDD) or the like for editing.
In the case of recording the video data and the audio data in the randomly accessible recording medium, these items of data are managed as a set of files (hereinafter referred to as the “clip”). For example, one clip is associated with main data file such as image data or audio data, a proxy data file, and a metadata file. The “main data” herein means video data and audio data as material of actual broadcasting data, and the main data is not compressed, or compressed at a relatively low compression ratio. The “proxy data” is compressed at a compression ratio that is higher than that for the main data. The “metadata” is information used for management of, e.g., reproduction of the main data file or the proxy data file.
In an actual shooting site or the like, editing is performed using proxy data as material to create broadcasting content data. For example, according to the disclosure of Patent documents 1, 2, an optical disk containing the recorded data is taken out from a video camera, and mounted in an optical disk drive. The proxy data is copied to a HDD in the optical disk drive for editing. Based on the edited proxy data, the main data is edited, and the final broadcasting content data is created.    Patent document 1: Japanese Laid-Open Patent Publication No. 2004-343217    Patent document 2: Japanese Laid-Open Patent Publication No. 2004-343218